Direct Lagrangian tracking simulation of droplet growth in vertically developing cloud

Yuichi Kunishima, Ryo Onishi
2018 Atmospheric Chemistry and Physics Discussions  
<p><strong>Abstract.</strong> We present a direct Lagrangian simulation that computes all the warm-rain processes in a vertically developing cloud, including cloud condensate nuclei (CCN) activation, condensational growth, collisional growth, and droplet gravitational settling. This simulation, which tracks the motion and growth of individual particles, is applied to a kinematic simulation of an extremely-vertically-elongated quasi-one-dimensional domain, after which the results are compared
more » ... lts are compared with those obtained from a spectral-bin model, which adopts the conventional Euler framework. The comparison results, which confirm good bulk statistical agreement between the Lagrangian and conventional spectral-bin simulations, also show that the Lagrangian simulation is free from the numerical diffusion found in the spectral-bin simulation. After analyzing the Lagrangian statistics of the surface raindrops that reach the ground, back-trajectory scrutiny reveals that the Lagrangian statistics of surface raindrops contains the information about the sky where the raindrops grow like the shape of snow crystals does.</p>
doi:10.5194/acp-2018-328 fatcat:cmksrmklzre4jgqcnkuimbxoky